/*
 * Copyright 2010-2020 Alfresco Software, Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.activiti.validation.validator.impl;

import java.util.HashMap;
import java.util.List;
import org.activiti.bpmn.model.BoundaryEvent;
import org.activiti.bpmn.model.BpmnModel;
import org.activiti.bpmn.model.CancelEventDefinition;
import org.activiti.bpmn.model.CompensateEventDefinition;
import org.activiti.bpmn.model.ErrorEventDefinition;
import org.activiti.bpmn.model.EventDefinition;
import org.activiti.bpmn.model.FlowElement;
import org.activiti.bpmn.model.MessageEventDefinition;
import org.activiti.bpmn.model.Process;
import org.activiti.bpmn.model.SignalEventDefinition;
import org.activiti.bpmn.model.TimerEventDefinition;
import org.activiti.bpmn.model.Transaction;
import org.activiti.validation.ValidationError;
import org.activiti.validation.validator.Problems;
import org.activiti.validation.validator.ProcessLevelValidator;

/**

 */
public class BoundaryEventValidator extends ProcessLevelValidator {

    @Override
    protected void executeValidation(BpmnModel bpmnModel, Process process, List<ValidationError> errors) {
        List<BoundaryEvent> boundaryEvents = process.findFlowElementsOfType(BoundaryEvent.class);

        // Only one boundary event of type 'cancel' can be attached to the same
        // element, so we store the count temporarily here
        HashMap<String, Integer> cancelBoundaryEventsCounts = new HashMap<String, Integer>();

        // Only one boundary event of type 'compensate' can be attached to the
        // same element, so we store the count temporarily here
        HashMap<String, Integer> compensateBoundaryEventsCounts = new HashMap<String, Integer>();

        for (int i = 0; i < boundaryEvents.size(); i++) {
            BoundaryEvent boundaryEvent = boundaryEvents.get(i);

            if (boundaryEvent.getEventDefinitions() != null && !boundaryEvent.getEventDefinitions().isEmpty()) {
                EventDefinition eventDefinition = boundaryEvent.getEventDefinitions().get(0);
                if (
                    !(eventDefinition instanceof TimerEventDefinition) &&
                    !(eventDefinition instanceof ErrorEventDefinition) &&
                    !(eventDefinition instanceof SignalEventDefinition) &&
                    !(eventDefinition instanceof CancelEventDefinition) &&
                    !(eventDefinition instanceof MessageEventDefinition) &&
                    !(eventDefinition instanceof CompensateEventDefinition)
                ) {
                    addError(errors, Problems.BOUNDARY_EVENT_INVALID_EVENT_DEFINITION, process, boundaryEvent);
                }

                if (eventDefinition instanceof CancelEventDefinition) {
                    FlowElement attachedToFlowElement = bpmnModel.getFlowElement(boundaryEvent.getAttachedToRefId());
                    if (!(attachedToFlowElement instanceof Transaction)) {
                        addError(errors, Problems.BOUNDARY_EVENT_CANCEL_ONLY_ON_TRANSACTION, process, boundaryEvent);
                    } else {
                        if (!cancelBoundaryEventsCounts.containsKey(attachedToFlowElement.getId())) {
                            cancelBoundaryEventsCounts.put(attachedToFlowElement.getId(), Integer.valueOf(0));
                        }
                        cancelBoundaryEventsCounts.put(
                            attachedToFlowElement.getId(),
                            Integer.valueOf(cancelBoundaryEventsCounts.get(attachedToFlowElement.getId()) + 1)
                        );
                    }
                } else if (eventDefinition instanceof CompensateEventDefinition) {
                    if (!compensateBoundaryEventsCounts.containsKey(boundaryEvent.getAttachedToRefId())) {
                        compensateBoundaryEventsCounts.put(boundaryEvent.getAttachedToRefId(), Integer.valueOf(0));
                    }
                    compensateBoundaryEventsCounts.put(
                        boundaryEvent.getAttachedToRefId(),
                        compensateBoundaryEventsCounts.get(boundaryEvent.getAttachedToRefId()) + 1
                    );
                } else if (eventDefinition instanceof MessageEventDefinition) {
                    // Check if other message boundary events with same message
                    // id
                    for (int j = 0; j < boundaryEvents.size(); j++) {
                        if (j != i) {
                            BoundaryEvent otherBoundaryEvent = boundaryEvents.get(j);
                            if (
                                otherBoundaryEvent.getAttachedToRefId() != null &&
                                otherBoundaryEvent.getAttachedToRefId().equals(boundaryEvent.getAttachedToRefId())
                            ) {
                                if (
                                    otherBoundaryEvent.getEventDefinitions() != null &&
                                    !otherBoundaryEvent.getEventDefinitions().isEmpty()
                                ) {
                                    EventDefinition otherEventDefinition = otherBoundaryEvent
                                        .getEventDefinitions()
                                        .get(0);
                                    if (otherEventDefinition instanceof MessageEventDefinition) {
                                        MessageEventDefinition currentMessageEventDefinition =
                                            (MessageEventDefinition) eventDefinition;
                                        MessageEventDefinition otherMessageEventDefinition =
                                            (MessageEventDefinition) otherEventDefinition;
                                        if (
                                            otherMessageEventDefinition.getMessageRef() != null &&
                                            otherMessageEventDefinition
                                                .getMessageRef()
                                                .equals(currentMessageEventDefinition.getMessageRef())
                                        ) {
                                            addError(
                                                errors,
                                                Problems.MESSAGE_EVENT_MULTIPLE_ON_BOUNDARY_SAME_MESSAGE_ID,
                                                process,
                                                boundaryEvent
                                            );
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            } else {
                addError(errors, Problems.BOUNDARY_EVENT_NO_EVENT_DEFINITION, process, boundaryEvent);
            }
        }

        for (String elementId : cancelBoundaryEventsCounts.keySet()) {
            if (cancelBoundaryEventsCounts.get(elementId) > 1) {
                addError(
                    errors,
                    Problems.BOUNDARY_EVENT_MULTIPLE_CANCEL_ON_TRANSACTION,
                    process,
                    bpmnModel.getFlowElement(elementId)
                );
            }
        }

        for (String elementId : compensateBoundaryEventsCounts.keySet()) {
            if (compensateBoundaryEventsCounts.get(elementId) > 1) {
                addError(
                    errors,
                    Problems.COMPENSATE_EVENT_MULTIPLE_ON_BOUNDARY,
                    process,
                    bpmnModel.getFlowElement(elementId)
                );
            }
        }
    }
}
